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updates

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-02-27 23:19:58 -08:00
parent c205b59a21
commit 31c68b6e23
6 changed files with 170 additions and 97 deletions
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82
src/sat/sat_local_search.cpp
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@ -21,6 +21,7 @@
#include "sat_solver.h"
#include "card_extension.h"
#include "sat_params.hpp"
#include "timer.h"
namespace sat {
@ -65,7 +66,7 @@ namespace sat {
void local_search::init_cur_solution() {
//cur_solution.resize(num_vars() + 1, false);
for (unsigned v = 0; v < num_vars(); ++v) {
cur_solution[v] = (rand() % 2 == 1);
cur_solution[v] = (m_rand() % 2 == 1);
}
}
@ -138,7 +139,7 @@ namespace sat {
init_cur_solution();
// init varibale information
// variable 0 is the virtual variable
// the last variable is the virtual variable
m_vars.back().m_score = INT_MIN;
m_vars.back().m_conf_change = false;
@ -169,8 +170,6 @@ namespace sat {
if (objective_value > best_objective_value) {
best_solution = cur_solution;
best_objective_value = objective_value;
stop = clock();
best_time = (double)(stop - start) / CLOCKS_PER_SEC;
}
}
@ -197,7 +196,8 @@ namespace sat {
}
}
local_search::local_search(solver& s) {
local_search::local_search(solver& s) :
m_par(0) {
// copy units
unsigned trail_sz = s.init_trail_size();
@ -264,7 +264,7 @@ namespace sat {
add_cardinality(lits.size(), lits.c_ptr(), n);
}
//
// optionally handle xor constraints.
// xor constraints should be disabled.
//
SASSERT(ext->m_xors.empty());
}
@ -273,24 +273,31 @@ namespace sat {
local_search::~local_search() {
}
void local_search::add_soft(int v, int weight) {
// TBD
ob_term t;
t.var_id = v;
t.coefficient = weight;
ob_constraint.push_back(t);
void local_search::add_soft(bool_var v, int weight) {
ob_constraint.push_back(ob_term(v, weight));
}
lbool local_search::check(parallel& p) {
flet<parallel*> _p(m_par, &p);
return check();
}
lbool local_search::check() {
return check(0, 0);
}
lbool local_search::operator()() {
lbool local_search::check(unsigned sz, literal const* assumptions) {
//sat_params params;
//std::cout << "my parameter value: " << params.cliff() << "\n";
unsigned num_constraints = m_constraints.size();
for (unsigned i = 0; i < sz; ++i) {
add_clause(1, assumptions + i);
}
init();
bool reach_cutoff_time = false;
bool reach_known_best_value = false;
bool_var flipvar;
double elapsed_time = 0;
//clock_t start = clock(), stop; // TBD, use stopwatch facility
start = clock();
timer timer;
timer.start();
// ################## start ######################
//std::cout << "Start initialize and local search, restart in every " << max_steps << " steps\n";
unsigned tries, step;
@ -309,25 +316,20 @@ namespace sat {
flip(flipvar);
m_vars[flipvar].m_time_stamp = step;
}
if (tries % 10 == 0) {
// take a look at watch
stop = clock();
elapsed_time = (double)(stop - start) / CLOCKS_PER_SEC;
std::cout << tries << ": " << elapsed_time << '\n';
}
if (elapsed_time > cutoff_time)
reach_cutoff_time = true;
if (reach_known_best_value || reach_cutoff_time)
IF_VERBOSE(1, if (tries % 10 == 0) verbose_stream() << tries << ": " << timer.get_seconds() << '\n';);
if (!m_limit.inc())
break;
}
if (reach_known_best_value) {
std::cout << elapsed_time << "\n";
}
else {
std::cout << -1 << "\n";
}
IF_VERBOSE(1, verbose_stream() << timer.get_seconds() << " " << (reach_known_best_value ? "reached":"not reached") << "\n";);
// remove unit clauses from assumptions.
m_constraints.shrink(num_constraints);
//print_solution();
std::cout << tries * max_steps + step << '\n';
IF_VERBOSE(1, verbose_stream() << tries * max_steps + step << '\n';);
if (m_unsat_stack.empty() && ob_constraint.empty()) { // or all variables in ob_constraint are true
return l_true;
}
// TBD: adjust return status
return l_undef;
}
@ -354,7 +356,7 @@ namespace sat {
case -2: // from -1 to -2
for (unsigned j = 0; j < c.size(); ++j) {
v = c[j].var();
// flipping the slack increasing var will no long sat this constraint
// flipping the slack increasing var will no longer satisfy this constraint
if (is_true(c[j])) {
//score[v] -= constraint_weight[c];
dec_score(v);
@ -378,7 +380,7 @@ namespace sat {
v = c[j].var();
// flip the slack decreasing var will falsify this constraint
if (is_false(c[j])) {
//score[v] -= constraint_weight[c];
// score[v] -= constraint_weight[c];
dec_score(v);
dec_slack_score(v);
}
@ -459,14 +461,13 @@ namespace sat {
vi.m_in_goodvar_stack = true;
}
}
}
bool local_search::tie_breaker_sat(bool_var v, bool_var best_var) {
// most improvement on objective value
int v_imp = cur_solution[v] ? -coefficient_in_ob_constraint.get(v, 0) : coefficient_in_ob_constraint.get(v, 0);
int b_imp = cur_solution[best_var] ? -coefficient_in_ob_constraint.get(best_var, 0) : coefficient_in_ob_constraint.get(best_var, 0);
//std::cout << v_imp << "\n";
// std::cout << v_imp << "\n";
// break tie 1: max imp
// break tie 2: conf_change
// break tie 3: time_stamp
@ -521,7 +522,7 @@ namespace sat {
}
// Diversification Mode
constraint const& c = m_constraints[m_unsat_stack[rand() % m_unsat_stack.size()]]; // a random unsat constraint
constraint const& c = m_constraints[m_unsat_stack[m_rand() % m_unsat_stack.size()]]; // a random unsat constraint
// Within c, from all slack increasing var, choose the oldest one
unsigned c_size = c.size();
for (unsigned i = 0; i < c_size; ++i) {
@ -534,13 +535,10 @@ namespace sat {
void local_search::set_parameters() {
srand(m_config.seed());
cutoff_time = m_config.cutoff_time();
m_rand.set_seed(m_config.seed());
s_id = m_config.strategy_id();
best_known_value = m_config.best_known_value();
if (s_id == 0)
max_steps = 2 * num_vars();
else {